"I think he'll be better," said Fox. "I think we'll be better as a football team. What people don't realize is last year really was our first year in an offense."

Nobody was sure how well or how bad Manning was going to play in his first year in Denver last season.

What we all know is how he ended up playing lights out.

Check out what Manning did in his first season with the Broncos.

Manning had a 105.8 passer rating last season, second only to Green Bay's Aaron Rodgers who had a 108 passer rating and his highest since 2004.

Manning completed 68.6 percent of his passes, tied with Atlanta's Matt Ryan for the best completion percentage in the league.

Manning threw 37 touchdown passes, third most last season and his most since 2004 when he threw 49.

Manning threw for 4,659 yards, the second most of his career and only 41 yards shy of his career high of 4,700 yards in 2010, his last year with the Indianapolis Colts.

Not only did Manning have one of his most productive seasons last year, but, as reported by USA TODAY's Lindsay H. Jones in February at the NFL scouting combine, Fox thinks Manning will be healthier for his second season in Denver.

"A lot was made of the neck and the surgeries. But in reality, it's a nerve situation, and it takes a while for nerves to grow," said Fox. "He's getting better every day. I think he'll be, health-wise, he'll be even better this year."

And then there's the addition of Welker to the receiving corps in Denver.

The Broncos signing of Welker to a two-year, $12 million deal last week gives the Broncos three receivers who all had 1,000-yard seasons in 2012. Demaryius Thomas had 1,434 receiving yards while Wes Welker had 1,354 and Eric Decker had 1,064 yards.

"When you're a passing attack and you've got (No.) 18, you're looking for three productive guys out there," Fox said to DenverBroncos.com's editor Gray Caldwell last week regarding the signing of Welker. "I think Wes Welker has proven as productive a slot receiver as there is really in recent NFL history."